Process for stabilizing alkaline hydrogen-peroxid solutions.



STATES PATENT onnicn.

i ALOIS SCHAIDHAUF, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO ROESSLER & HASSLACHER CHEMICAL COMPANY, OF NEW YORK, N. Y., A

CORPORATION OF GERMANY.

PROCESS FOR STABILIZING ALKALINE HYDROGEN-PEROXID SOLUTIONS.

No Drawing.

by first nearly or entirely neutralizing the alkali by a strong acid or by some suitable salt of neutral reaction, as for instance magnesium chlorid or calcium chlorid.

Such processes have even been applied in those cases in which fibers offering great resistance to alkali have been subjected to bleaching.

It has been considered a settled fact tlat ecompose most quickly at the usual temperature and especially at the high temperatures applied in bleaching processes. The same conditions prevail when an aqueous solution of pure hydrogen-peroxid is diluted to the proper concentration necessary for bleaching processes and for these purposes is furthermore rendered alkaline. Undoubtedly free caustic alkali exerts a strongly decomposing action on the hydrogenperoxid, necessitating, in the case of using sodium-peroxid, the neutralization of the alkali by nearly or absolutely equivalent quantities of strong acid or suitable salts respectively. Such treatment causes the formation of an objectionable mud or sediment in the bath.

I have discovered that the decomposing action of the caustic alkali instead of forming mud or sediment in the bath during the process because of the addition of the considerable quantities of acid or compound respectively, may conveniently be counteracted by slight additions of a soluble mag nesium salt, said compound being insufiicient in quantity to cause the formation of any mud or sediment which in some way or other might play the part of a disturbing elementthe results obtained by the use of soluble magnesium salts are even surpassed by magnesla or magnesium salts in combi- Specification of Letters Patent.

Application filed ma 1, 1918. Serial No. 764,738.

Patented May 2, 1916.

nation with a suitable silica compound or silicates. I

The following experiments illustrate the elficiency of my new process: I

1. 0.2 g. Na O dissolved in 100 cc. of pure water heated for 1 hour at 85 C. had lost all oxygen.

2. 0.2 g. Na Q in 10000. of water plus 0.015 g. crystallized waterglass had lost all oxygen after one hour.

3. 0.2 g. Na Q in 100 cc. of water plus 0.012 g. crystallized MgCl showed, after being at 85 C. for 1 hour, still 40%, for

2 hours, still 10.7%, for 3 hours, still 3.8%, of the original amount of 0 gen.

. 4. 0.2 g. Na O in 100 cc. of water plus 0.015 g. ofcryfiallized waterglass plus 0.012 g. crystalhzed MgCl showed after 1 hour 18% 2 hours 20%, 3 hours 10.3%, of the original amount of oxygen.

In many countries there may be water which occasionally carries the amount of soluble magnesium salt or the silicon-magnesium compound necessary to stabilize the solutions of sodium-peroxid or to respectively counteract the decomposing influence of the caustic alkali on the hydrogen-peroxid solutions. In such cases one need only dissolve the necessary quantity of sodium-peroxid and immediately obtains a stable alkaline bleaching bath. If the water one has at disposal does not containat all the co nst1tuents coming here into question, or if it does not carry the same in proper proportion, or if there is only one of the constituents present, one may quickly ascertam by a simple experiment, which chemicals and what quantities of the same must be added to surely obtain the desired eflect and where in the claims I refer to water naturally containing in solution magnesia or magnesium salts or a suitable magnesium and silicon compound, I mean to includeappended claims debath a soluble magnesium compound in a quantity insuflicient to create a precipitate of mud in said bleaching bath.

2. The process of stabilizing bleaching baths containing hydrogen peroxid in an alkaline solution, consisting in adding to the bath a quantity of a soluble magnesium compound and proportionately of a soluble silicon compound, said quantity being insufficient to create a precipitate of mud in the bleaching bath.

3. The process of stabilizing bleaching baths containing hydrogen peroxid in an alkaline solution, consisting in adding to the bath a quantity of a soluble magnesium compound and proportionately of a soluble silicate, said quantity being insuilicient to 1c)reate a precipitate of mud in the bleaching ath.

4. The process of stabilizing bleaching baths containing hydrogen Peroxid in an alkaline solution, consisting in adding to the bath a quantity of a soluble magnesium salt, and proportionately of a soluble silicate, said quantity being insufficient to create a precipitate of mud in the bleaching bath.

5. The process of stabilizing bleaching baths containing hydrogen peroxid'in an alkaline solution, consisting in adding to the bath a quantity of a soluble magnesium salt and proportionately of a soluble silicon compound, said quantity being insufiicient to create a precipitate of mud in the bleaching bath.

6. The process for making a stable bath containing hydrogen peroxid in an alkaline solution, consisting in dissolving sodium peroxid in water containing in solution magnesia, or magnesium salts.

7. The process for making a stable bath containing hydrogen peroxid in an alkaline solution, consisting 1n dissolving sodium peroxid in water naturally containing in solution a suitable magnesium and silicon compound.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALOIS SCHAIDHAUF. Witnesses:

JEAN GRUND, CARL GRUND. 

